Respuesta :

Answer:

work done against friction: (a) if a body is moved horizontally against the frictional force this type of work is work done against friction.

(b) for example sliding a box and rolling a drum

work done against gravity: (a) if a body is moved vertically upwards against the gravity of the earth, this type of work is work done against gravity

(b) for example lifting and throwing of a body upward

Step-by-step explanation:

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